What medical conditions is cannabis approved for?

Approved cannabinoid drugs: Epidiolex (purified CBD): FDA-approved for Dravet syndrome, Lennox-Gastaut syndrome, tuberous sclerosis complex (severe epilepsy). Sativex/nabiximols (THC:CBD 1:1 spray): approved in 32 countries for MS spasticity. Dronabinol (synthetic THC, Marinol/Syndros): FDA-approved for AIDS wasting syndrome and chemotherapy-induced nausea/vomiting. Nabilone (synthetic THC analogue): FDA-approved for chemotherapy-induced nausea. Evidence supports (but most countries haven't formally approved the plant): neuropathic pain (second-line), cancer pain, MS spasticity, glaucoma (limited effect, better drugs exist), PTSD (limited evidence). Many medical cannabis programmes offer it for conditions with limited or no rigorous evidence — the legal framework is often ahead of the science.

Is medical cannabis safe?

Safety depends critically on: (1) Which cannabinoid: CBD has an excellent safety profile — no psychosis risk, no addiction, no significant cognitive effects. THC has a significantly more complex risk profile. (2) Dose and frequency. (3) Age of user: adolescent use carries substantially higher risks (psychosis, cognitive development, academic outcomes). (4) Route: smoking cannabis shares tobacco's cardiovascular and respiratory risks; vaporisation, oral and sublingual routes are safer. Most important risks of THC: cannabis use disorder (9% of all users, 50% of daily users); psychosis/schizophrenia risk with high-potency cannabis (OR 5.1 in daily high-potency users, Di Forti 2019); cognitive impairment during acute intoxication (driving impairment — blood THC level correlates imperfectly with impairment); drug interactions (CBD inhibits CYP3A4/CYP2C19).

Why is cannabis illegal in most countries if it has medical uses?

Historical context: cannabis was classified as a Schedule I substance under the 1961 UN Single Convention on Narcotic Drugs — meaning "no currently accepted medical use and high potential for abuse" — based on the scientific evidence and political context of the 1960s. This classification made research extremely difficult for 50 years. WHO's 2019 expert review recommended reclassification: in December 2020, the UN Commission on Narcotic Drugs voted to remove cannabis from Schedule IV (most restrictive) while retaining Schedule I (international control) — acknowledging therapeutic value. Individual country legislation governs medical cannabis programmes, creating enormous variation globally. The tension between evidence-based scheduling and political/cultural/historical factors continues to drive cannabis policy debate.

What is the risk of cannabis and psychosis?

The evidence is now clear that high-potency THC cannabis increases psychosis risk in vulnerable individuals: Di Forti et al. 2019 (Lancet Psychiatry): daily use of high-potency (>10% THC) cannabis associated with 5× increased odds of first-episode psychosis vs never-users. Population attributable fraction suggests high-potency cannabis causes 12-30% of first-episode psychosis cases in cities where it dominates the market. Biological plausibility: THC activates CB1 receptors on dopaminergic neurons in the striatum and prefrontal cortex, increasing dopamine release — the mechanism thought to drive psychosis susceptibility. CBD has antipsychotic properties and may partially mitigate THC's psychotogenic effects — suggesting high-CBD, low-THC preparations have a better safety profile.

Does CBD work for anxiety and sleep?

For anxiety: clinical evidence is promising but limited. Several small RCTs and open-label studies show benefit for generalised anxiety disorder and social anxiety disorder with CBD doses of 300-600mg. The evidence base is substantially weaker than for established treatments (SSRIs, CBT). For sleep: limited evidence; CBD may reduce anxiety-related insomnia indirectly. No large RCTs. Major caution: most CBD consumer products (gummies, oils, beverages) contain far lower doses than used in clinical trials, and product purity/content is highly variable in unregulated markets. UK FSA: CBD consumer products require a Novel Food Authorisation; maximum recommended dose 70mg/day. A CBD gummy with 10mg CBD per piece and a clinical trial using 300mg are not the same thing.

How does GMJ News cover medical cannabis?

GMJ News covers FDA-approved cannabinoid drugs (Epidiolex, Sativex, dronabinol), the endocannabinoid system, pain evidence (Cochrane — modest, second-line), the THC psychosis risk (Di Forti 2019 — the key safety data), cannabis use disorder, adolescent brain development risks, the evolving legal landscape (Germany 2024), CBD vs THC risk profiles, the entourage effect debate, and consumer product evidence gaps. GMJ position: specific cannabinoid preparations have genuine, FDA-approved medical uses; the THC psychosis risk is real and dose-dependent; CBD has a much better safety profile; the legal landscape is evolving faster than the evidence.

Home › Topics › Medical Cannabis

Medical Cannabis

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Medical cannabis — encompassing plant-derived cannabinoids (THC, CBD) and their synthetic analogues acting on the endocannabinoid system (CB1 and CB2 receptors) — has moved from taboo to mainstream medicine with FDA approval of Epidiolex (purified CBD) in 2018 for rare childhood epilepsies (Dravet syndrome, Lennox-Gastaut syndrome — reducing seizure frequency by approximately 40%), approval of Sativex (THC:CBD oromucosal spray) in 32 countries for MS spasticity, and Cochrane-level evidence for modest analgesic benefit in neuropathic pain and cancer pain — while more than 50 countries have legal medical cannabis frameworks and Germany legalised recreational cannabis in 2024 (WHO). The critical risk that must accompany every clinical discussion: high-potency cannabis (>10% THC) is associated with a 5-fold increased risk of schizophrenia, and cannabis use disorder affects approximately 9% of all users and 50% of daily users — making the therapeutic window vs harm profile highly dependent on THC:CBD ratio, dose, age of initiation and genetic susceptibility.

Key messages

Epidiolex (CBD) — FDA approved 2018 for severe childhood epilepsy

Epidiolex (purified cannabidiol, GW Pharmaceuticals/Jazz Pharmaceuticals) was FDA-approved in June 2018 for Dravet syndrome and Lennox-Gastaut syndrome — two rare, severe, treatment-refractory childhood epilepsies — reducing seizure frequency by approximately 40-50% vs placebo (New England Journal of Medicine, 2017). This was the first FDA-approved plant-derived cannabinoid drug. It was subsequently approved for tuberous sclerosis complex (2020).

Sativex — approved in 32 countries for MS spasticity

Nabiximols (Sativex, GW Pharmaceuticals) — THC:CBD 1:1 oromucosal spray — is approved in 32 countries (including UK, Germany, Canada, most of EU) for the treatment of spasticity in multiple sclerosis. Cochrane 2018: statistically significant reduction in patient-reported spasticity NRS scores vs placebo; modest clinical benefit. Not FDA-approved in the USA.

Pain — modest evidence, not comparable to opioids

Cochrane 2018 systematic review of cannabinoids for chronic neuropathic pain: moderate-quality evidence for modest analgesic benefit (NNT approximately 10-20 for ≥50% pain reduction — substantially less effective than opioids or NSAIDs for most patients). Some evidence for cancer pain and MS pain. Cannabinoids are a second- or third-line option for neuropathic pain not responding to first-line treatments (duloxetine, pregabalin, amitriptyline).

THC and psychosis risk — the most critical safety warning

High-potency cannabis (>10% THC) is independently associated with a 5-fold increased risk of schizophrenia and psychotic disorders (Di Forti et al., Lancet Psychiatry 2019). Cannabis use disorder affects approximately 9% of all users and approximately 50% of daily users. Adolescent cannabis use is particularly harmful: associated with reduced educational attainment, IQ reduction and increased psychosis risk during a critical neurodevelopmental period. CBD does not cause psychosis and has antipsychotic properties — highlighting that THC and CBD have fundamentally different risk profiles.

The legal landscape — rapidly evolving

50+ countries have some form of medical cannabis programme. Germany legalised recreational cannabis in April 2024 — the first EU country to do so. WHO 2020: removed cannabis from Schedule IV (most restrictive) of the 1961 Single Convention while retaining Schedule I (international control). USA: FDA has not approved cannabis (the plant) for medical use, though individual cannabinoid drugs (Epidiolex, dronabinol, nabilone) are approved.

THC:CBD ratio — the clinically critical variable

THC (Δ9-tetrahydrocannabinol): psychoactive; analgesic; antiemetic; increases appetite; psychosis risk (dose-dependent). CBD (cannabidiol): not psychoactive; anticonvulsant (Epidiolex); anxiolytic (modest evidence); antipsychotic properties; anti-inflammatory (preclinical). Most evidence for efficacy: THC-containing preparations. Most safety concerns: THC. The therapeutic window for THC-dominant preparations is narrow; CBD-dominant preparations have better safety profiles. The "entourage effect" (whole plant superior to individual cannabinoids) is biologically plausible but not definitively proven.

Key statistics

FDA June 2018

Epidiolex (CBD) approved for Dravet syndrome and Lennox-Gastaut syndrome

FDA 2018

~40-50%

seizure frequency reduction with Epidiolex vs placebo

NEJM 2017

32 countries

have approved Sativex (THC:CBD) for MS spasticity

GW Pharma

5×

higher schizophrenia risk with high-potency (>10% THC) cannabis (Di Forti 2019)

Lancet Psychiatry 2019

of all cannabis users develop cannabis use disorder (50% of daily users)

WHO/UNODC

50+

countries have some form of medical cannabis programme

WHO 2024

Medical cannabis evidence strength by indication — Cochrane/FDA assessment

Source: Cochrane/FDA. Epilepsy (Epidiolex) strongest; pain and spasticity moderate; most other uses insufficient.

Glossary of key terms

Endocannabinoid system
PharmacologyThe body's endogenous cannabinoid system: CB1 receptors (predominantly CNS — brain, spinal cord — and adipose tissue; mediate psychoactive and analgesic effects of THC) and CB2 receptors (predominantly immune cells; mediate anti-inflammatory effects). Endogenous ligands: anandamide (AEA) and 2-arachidonoylglycerol (2-AG) — endocannabinoids synthesised on demand from membrane phospholipids, released retrogradely across synapses. Functions: pain modulation; appetite regulation; memory and learning; immune regulation; stress response. This physiological system explains why exogenous cannabinoids (THC, CBD) have widespread effects in the body.

Epidiolex (cannabidiol, CBD)
FDA 2018/EMA 2019Purified cannabidiol from Cannabis sativa, manufactured by GW Pharmaceuticals (now Jazz Pharmaceuticals). FDA approved June 2018 for: Dravet syndrome (rare genetic epilepsy, SCN1A mutation, multiple daily seizures from infancy); Lennox-Gastaut syndrome (catastrophic childhood epilepsy); tuberous sclerosis complex (2020). Mechanism of anticonvulsant action: not via CB1 receptors — CBD works through multiple mechanisms including TRPV1 channel activation, GPR55 antagonism, and modulation of adenosine signalling. CBD does not produce psychoactive effects or cannabis use disorder.

Cannabis use disorder (CUD)
DSM-5/ICD-11A substance use disorder characterised by: failure to control cannabis use despite harmful consequences; craving; tolerance; withdrawal (dysphoria, irritability, insomnia, anorexia — 1-2 weeks after cessation in heavy users). Prevalence: approximately 9% of all cannabis users; approximately 17% of adolescent initiators; approximately 50% of daily users. Risk factors for CUD: early onset (adolescence); daily use; high-THC preparations; genetic vulnerability; co-occurring mental health disorders. Evidence-based treatments: motivational enhancement therapy; CBT; contingency management. No FDA-approved pharmacotherapy for CUD (though some medications show modest benefit).

Di Forti psychosis study
Lancet Psychiatry 2019A multi-site European case-control study (EU-GEI, 11 sites in 10 countries): 901 cases of first-episode psychosis + 1,237 controls. Key findings: high-potency cannabis use (>10% THC) associated with adjusted OR 3.2 for first-episode psychosis (vs never-users). Daily high-potency cannabis use: OR 5.1. Population attributable fraction: if high-potency cannabis were unavailable, approximately 12% of first-episode psychosis cases in Amsterdam, 30% in London (where high-potency cannabis dominates the market) would be prevented. This is the strongest epidemiological evidence to date that high-THC cannabis causes psychosis in susceptible individuals.

The entourage effect
Research/DebateThe hypothesis (Ethan Russo, 2011) that the multiple phytocannabinoids, terpenes and flavonoids in the whole cannabis plant interact synergistically — producing therapeutic effects greater than any isolated compound. This has been used to argue that whole-plant preparations are superior to purified CBD or THC. The evidence: plausible in preclinical studies; not definitively proven in clinical trials. Some terpenes (myrcene, linalool) have measurable pharmacological effects. Critically: the entourage effect hypothesis is also used to justify unsubstantiated marketing claims and to discourage use of evidence-tested isolated compounds (like Epidiolex). The scientific jury is still deliberating.

Germany 2024 — recreational legalisation
EU/RegulatoryGermany became the first major EU country to partially legalise recreational cannabis in April 2024 — allowing adults to possess up to 25g and grow up to 3 plants at home, and establishing social cannabis clubs. This followed Canada (2018), multiple US states, the Netherlands (coffee shops, de facto legal), and Uruguay (2013). Germany specifically did NOT establish a commercial retail market initially. The EU Schengen area implications are significant — cannabis purchased legally in Germany cannot legally cross borders. The public health evidence on recreational legalisation effects on CUD rates, adolescent use and road safety is being closely monitored.